Rotary lawn sprinkler



July 18, 1961 o, NORLAND 2,992,780

ROTARY LAWN SPRINKLER Filed Dec. 26. 195'? WV NTOR. fig-fig; 53 4 w United States Patent 9 2,992,780 ROTARY LAWN SPRINKLER Daniel 0. Norland, 5632 E. Lincoln St., Cypress, Calif. Filed Dec. 26, 1957, Ser. No. 705,360 1 Claim. (Cl. 239-231) This invention relates to lawn sprinklers and more particularly relates to rotary lawn sprinklers.

Reference is made to Patents Nos. 1,950,512 and 2,745,- 698, issued respectively to my father and to myself. These patents relate generally to sprinklers in which a jet of water strikes upon a disk, causing the disk to rotate. Either by vibration or by hammer action, the rotating disk transmits torque to the whole sprinkler head.

There are presently on the market a considerable num-- ber of rotary sprinklers embodying variations of the same principles. In all that have come to my attention, it has been accepted that the water jet has a certain amount of force, which may be great or small according to the relative sizes of the jet opening and the valve opening; and the inventive efiort has been applied to utilizing that force to the greatest advantage. The force of the water jet, of course, depends on its mass and velocity; these in turn depend on the pressure; given certain passage sizes or amounts of throttling, the force of the jet has been considered as a function of the pressure in the water mains.

Jet efiiciency is to a large extent dependent on turbulence in the jet and the passage from which the jet issues. A passage of X cross-area can accommodate more water with higher velocity and less pressure drop, if turbulence in the passage is cut down. This is a factor which heretofore has not been taken into consideration in the design of sprinklers, but which I have found to be of the highest importance. In fact, so greatly has a reduction in jet turbulence improved sprinkler operation, that it has, in combination with other slight but important changes in structure, enabled me to build sprinklers of simplified design and small size which do the work heretofore requiring large and complex sprinklers.

It is an object of my invention to provide a rotary lawn sprinkler which will Water a large area with a minimum of main pressure.

Another object of my invention is to provide a rotary lawn sprinkler which may be very economically manufactured.

Still another object of my invention is to provide a rotary lawn sprinkler so constructed and balanced as to rotate with a minimum of applied force.

Other objects and advantages of my invention will become apparent as the following specification proceeds.

In the accompan u'ng drawing, FIG. 1 is an elevational view of a rotary lawn sprinkler according to the present invention, parts of the lower portion of the sprinkler and of the supporting water pipe being shown broken away;

FIG. 2 is a top plan view of the same;

FIG. 3 is a vertical sectional view on an enlarged scale of the water-jet arm of the sprinkler; and

FIG. 4 is a transverse sectional view on the line 44 of FIG. 3.

Having reference now to the details of the drawing, I have shown in FIG. 1 a rotary lawn sprinkler having a revolving head 5 which is supported on a nipple 6 journalled in a nut 7. The nut 7 has at its lower end a waterpipe 9, and above the threads 8 it has a hexagonal head 10 for the application of a tool for turning it. The nipple 6 extends below the nut 7 and is threaded at its lower extremity 11 to receive a nut 12. Between the nut 12 and the nut 7 are two washers 13 and 14. The lower washer 13 may be of any suitable material, for example rubber, or plastic, or rubber-impregnated paper or cloth; and the upper washer 14 is of pressed graphite.

The revolving head 5 is secured to the nipple 6 so that they revolve together, and to afford better rotation it is balanced upon the nipple 6. The head 5 comprises a jet arm 16 and a counter-balancing arm 17. To the jet arm 16 there is secured a propulsion mechanism substantially the same as that described in the aforementioned Patent 1,950,512. A lug 18 depends from the jet arm 16 and contains a screw 19. Encircling the shank of this screw is the looped lower end 20 of an upwardly projecting rod 21. Between the loop 20* and the head of the screw 19 is one end of a tension plate 22. The other end of this tension plate 22 is bifurcated, as at 23, and encompasses a lug 24 that projects from the side of the jet arm 16. When the screw 19 is tightened, the looped end 20 of the rod 21 is very firmly clamped to the tension plate 22 and the lug 18, and is thus held in adjusted position.

Secured to the rod 21 a short distance above the looped end 20 thereof is a collar 25, and mounted to rotate freely upon the rod 21 just above the collar 25 is the hub 26 of a disk 27. The undersurface of the disk 27 is uniformly serrated or notched as shown at 28. On the upper surface of the disk 27 and radial to the disk is a thickened portion or weight 29, which causes the disk 27 to be unbalanced upon the axial rod 21. In this respect the present sprinkler differs from that shown in Patent 1,950,512, in that in the patent the unbalancing weight of the patented sprinkler is on the bottom of the disk. Two very important advantages result from placing the weight on the top of the disk. In the first place, the serrations 28 may then be made uniform and therefore less costly to manufacture. In the second place, the uniform serrations give the disk 27 a better drive.

Above the hub 26 the rod 21 is threaded to receive a cap nut 30. A washer 31 may be inserted between the hub 26 and nut 30 to reduce friction. The cap nut 30 may be tightened on the rod 21 without coming into contact with the washer 31 or hub 26, permitting free rotation of the hub.

To eifect rotation of the disk 27, a jet of water is brought from the water pipe 9 through the nipple 6 into the rotating head 5, and thence through a water passage 34 in the jet arm 16 (see FIG. 3) to a jet nozzle 33 discharging against the serrations 28 on the disk 27. The disk 27, unbalanced by the weight 29, revolves with a strong vibration, which sets up a torque causing the entire head 5 to revolve. This method of causing rotation of a sprinkler head is, of course, old, being shown in Patent 1,950,512, beforementioned; what is novel in the present invention is the formation of the passages for water through the jet arm 16 and the jet nozzle 33. Instead of being circular in cross section the passage 34 in the jet arm 16 has a plurality of angles and flat sides and the passage 35 in the jet nozzle 33 may be shaped in the same manner, although this latter is not essential. The fiat-sided passage 34, although straight for substantially only the length of the jet arm 16, yet is effective to reduce turbulence in the jet of water. Each of the angles of the passage 34 is like a channel, straightening out the flow of the water and preventing the water from whirling. The sharper the angles, the greater is the channel effect. A triangular passage is ideal from the point of view of reduction of turbulence, although not ideal for capacity. I have shown a square passage in FIG. 4, and it is to be understood that the passage 34 may be three, four, five, or six sided. Beyond six sides, the interior angles are too obtuse to have :much channeling effect.

The jet nozzle 33 may be dispensed with entirely, if desired, and its water passage 35 need not be the same size and shape as the passage 34. As the nozzle 33 is applied by threads to the end of the passage 34, the

exact orientation (relative to the passage 34) of the passage 35 will often be doubtful. In any event, the length of the passage '35 is so short as to be ineffective in setting up turbulence again.

The counter-balancing arm 17 of the revolving head 5 is constructed so as actually to counter-balance as nearly aspossible, the jet arm 16 and the attached disk 27 with its various weights and lugs. The disk 27 is at one side of the center line of the jet arm 16 so that the jet issuing from the nozzle 33 will strike the serrations 28 near the outer edge of the disk, for greater effect. The center of gravity of the arm 16 and the attached appurtenances is not quite constant, due to the rotation of the weight 29, but it may be approximated closely, as shown in FIG. 2. The counter-balancing arm 17 is disposed as a balanced extension upon the center-of-gr'avity line of the arm 16 and attachments, rather than as an extension of the axis of the arm 16. Thus the torque set up by rotation of the weight 29 is transmitted to a substantially accurately balanced revolving mass, and the resultant revolutions of the head 5 are smooth, constant, and efiicient.

To facilitate rotation of the head 5, the washer 14 is of graphite, as hereinbefore mentioned. Water pressure upon the bottom of the nipple 6 tends to lift the nipple and the whole revolving head 5, opening a space and preventing friction between the head and the nut 7, as shown in FIG. 1, and causing the graphite washer 14 to bear against the bottom of the nut 7, which it lubricates. In use, the graphite washer 14 tends to wear, but such leakage of water as occurs takes place along the outside of the 'nipple 6, between the nipple and the nut 7. The graphite is entrained by the water between the nipple and the nut, and helps to seal this source of leakage as well as to provide lubrication in an area which otherwise is prone to fill with sand.

The disclosed embodiment is not to be construed as a limitation upon the invention, the scope of which is deemed to include any desirable constructive modification within the spirit and breadth of the appended claim.

I claim: In a rotary sprinkler, a head mounted revolvably and having a laterally extending arm, means on said am mounted revolvably and adapted by rotation to cause torque whereby said head is rotated, and a water passage in said head extending therethrough and through said arm for projecting a stream of water against said torquecausing means to cause rotation of said means, that portion of said water passage in said arm being straight for substantially the length of said arm and being fiat sided in cross-section so as to provide longitudinally extending channels for channelizing the flow of water therein, said flat-sided water passage having not more than six sides.

References Cited in the file of this patent UNITED STATES PATENTS 1,322,093 Bucherer Nov. 18, 191 9 1,375,948 Wilson Apr. 26, 1921 1,515,214 Kelleher et al. Nov. 11, 1924 1,950,512 Norland Mar. 13, 1934 2,002,178 Henry May 21, 1935 2,032,064 Meng Feb. 25, 1936 2,090,406 Thompson Aug. 17, 1937 2,212,008 Buelna a; Aug. 20, 1940 2,423,260 Slaughter July 1, 1947 2,582,158 Porter Ian. 8, 1952 2,595,114 Wieseltier Apr. 29, 1952 2,610,089 Unger Sept. 9, 1952 2,700,577 Oace Jan. 25, 1955 2,712,198 Smith -1 July 5, 1955 2,712,457 Kimbro July 5, 1955 2,714,037 Singer et al. July 26, 1955 

